Composite panels are usually made of wood, agriculture or other fibers by a manufacturing process leading to a production of panels in the form of hardboard, oriented strand board, fiber board siding, wafer board, medium density fiber board, particle board, and other similar boards. Typically, wood is the preferred fiber. The panels or boards are made by mixing fiber and a binder and then placing the mixture in a hot press. Wood-fiber based composites are sensitive to moisture, particularly moisture in a liquid form. In addition to linear expansion and thickness swell, moisture can cause blistering and fiber-pop at the panel surface. Since fiberboard is often painted or coated, especially for decorative use, blistering and fiber-pop become important issues, especially when using water based topcoats or adhesives. Tempering is often employed to yield a strong surface layer that gives added strength, especially to doorskins used in the manufacturing of doors. During building construction or transport of the finished composite, structural panels are often exposed to weather elements before they are protected by a siding or roofing. Severe weather can cause water damage to unprotected panels in a very short period of time. To protect the paneling during the construction process, a tempering topcoat is sometimes applied to the panel's surfaces to provide them with a hard, moisture resistant surface.
Usually, the process of manufacturing these composite panels includes a use of a tempering oil which is applied to the surfaces of the panel in order to impart a smooth, strong, and water resistant surface thereto. However the manufacturing technology often requires a high temperature bake oven in order to cure the tempering oil after it has been applied to the surface of the panel.
The above described processes have numerous drawbacks, including the release of VOCs, hazardous air pollutants (HAPs), and styrenes. The cost of energy for hot presses or ovens to cure the resins or shape the boards and the carbon emissions from the generation of the energy are additional considerations that motivate seeking an alternative way to make composite building materials.
Although wood continues to be a favored material for boards, and even though wood is one of the most successful renewable resources, the fact is that there simply are not enough big trees in world to satisfy the demand for boards from solid wood. Therefore, smaller trees are chipped and the chips combined with resins and other ingredients to make composite boards in order to meet demand.
Other construction materials may be derived from wood, or projects use alternative materials such as, for example, concrete, plastic, or steel. Each material has certain advantages and disadvantages in its manufacturing process, financial costs, or performance characteristics.
There is a need therefore, for a manufactured composite building material that does not rely primarily on wood and that does not require heat curing or pressing and that emits minimal pollutants and other undesirable by-products of manufacture; and which can be finished into a wide variety of appearances for household and industrial uses.